Add everyone, press Draw, then send each person their own link on WhatsApp. Nobody, not even you, sees who drew whom.
Keep couples or housemates apart.
Each link opens only that person's match. Send it to them alone; don't open other people's links.
The draw happens on this phone; nothing is sent to a server. Each match is tucked into its link in a scrambled form so it can't be read at a glance. That's a courtesy, not encryption. Your list and links are kept on this device so you can come back and finish sending.
Tap the gift to see who you're buying for
Keep it secret! Screenshot this if you'll need it later.
This link looks broken or incomplete. Ask your organiser to send it again.